<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			

			div{
				width: 123px;
				height: 123px;
				padding: 20px 40px;

				/*border: 8px solid #000000;*/
				border: 1px solid red;

			}
		</style>
	</head>
	<body>
		<!-- div不设置宽高的话，默认宽度是整个父容器，高度是0 -->
		<div></div>
		
	</body>
</html>
